1. Field of the Invention
The present invention generally relates to a touch-sensing display panel, and more particularly, to an in-cell type capacitive touch-sensing display panel.
2. Description of Related Art
The increasing progress of display technologies brings about great conveniences to people's daily life. As such, flat panel displays (FPDs) have become popular due to its features of being light and thin. Recently, all type of electronic products are developed toward easy operation, small volume, and large screen, and the demands of the volume and the screen size in the portable products are particularly stringent. Besides, in many electronic products, a touch sensing design is integrated into a display panel, so as to expand the area where the screen is disposed by removing the space for placing the keyboard or the operation buttons.
Generally, touch-sensing display panel includes a plurality of display units and a plurality of touch-sensing units, wherein the plurality of display units constitute a display panel and the plurality of touch-sensing units may be built in the display panel or added on a surface of the display panel. Based on different ways of sensing, touch units are generally categorized into resistant touch-sensing units, capacitive touch-sensing units, optical touch-sensing units, sonic wave touch-sensing units, and electromagnetic touch-sensing units. When the touch-sensing display panel is touched by fingers of users or a stylus, electrical characteristics (e.g. capacitance, current, resistance and so on) of the touch-sensing units located at the position that is touched by fingers or stylus changes. The aforesaid change of electrical characteristics is converted into electrical signal and processed by processor such that an command is output to control electronic devices.
Usually, touch-sensing pads of touch-sensing display panels are fabricated by transparent conductive layer. For example, the material of the transparent conductive layer is indium tin oxide (ITO). The transmittance of the transparent conductive layer ranges from about 90% to 98%. However, the transmittance of the areas outside of the touch-sensing pads is different from the transmittance of the areas occupied by the touch-sensing pads. Specifically, the transmittance of the areas outside of the touch-sensing pads is greater than the transmittance of the areas occupied by the touch-sensing pads. In this case, users may notice the difference of transmittance when using the conventional touch-sensing display panel. Accordingly, the display quality of the conventional touch-sensing display panel deteriorates. Currently, how to integrate touch-sensing units into display panels without deteriorating display quality (e.g. brightness) is an important issue to be solved immediately.